Current conduction through low angle grain boundaries in YBa₂Cu₃O₇₋₈ thin films studied magnetometrically

Taking advantage of the sensitivity of SQUID-based instrumentation and a simple ring geometry that facilitates the calculation of a current in the sample, we introduce a new magnetometric method to obtain the critical current density flowing through grain boundaries in the high-temperature superconductor YBa2Cu307-8 (YBCO). Since all magnetic moments originate from moving charges or electrical currents, an electrical current flowing in a simple configuration can be calculated from its magnetic moment or vice versa. Ring shaped YBCO films with or without [001]-tilt grain boundary were made on SrTiO3 substrates on surfaces perpendicular to the c-axis. Magnetic moments of rings containing 1.8°, 2.8°, 5.1°, and 7° [001]-tilt grain boundaries were measured at various temperatures and fields parallel to the c-axis; as well, rings with no grain boundaries were measured for comparison. Current densities of the samples were calculated from the measured magnetic moments using a modified Bean critical state model. Especially, we could extract a pure grain boundary current density (current flowing across the grain boundary) from the total magnetic moment of a grain boundary ring. An abrupt decrease of the current density was observed as the grain boundary angle increased. Even small misorientations of 1.8° \u3c\u3c$\u27\u3c5.1° diminish the current density by a large amount, while a 1.8° grain boundary does not. Moreover, large peaks were formed in curves of magnetic moment versus field for grain boundary samples under conditions of decreasing magnetic field (but not increasing field history). The appearance of a large peak in the m(H) curves of a grain boundary sample can be explained by the weak-link behavior of a small angle grain boundary. The high sensitivity of the magnetic moment and the grain boundary current density to field changes on a grain boundary strongly bolsters the weak-link interpretation of small angle grain boundaries

COMPARATIVE ANALYSIS OF RURAL AND URBAN START-UP ENTREPRENEURS

This study investigates the reasons for apparent differences in entrepreneurship rates in rural and urban areas using a Survey of Rural Kentucky Residents (SRKR) and the Panel Study of Entrepreneurial Dynamics (PSED) data. We estimate the determinants of dissimilar characteristics for rural and urban areas in two aspects: one is individual and contextual resources; the other is cultural tendencies of resources. The results of the analysis suggest that the difference in available individual, economic, and social support resources does not explain the observed difference in entrepreneurship rate. The results also indicate that gender, ethnicity, income, and number of children in the family have different effects on entrepreneurial intentions in rural and urban settings. The results suggest that policy makers need to account for cultural or geographical differences when designing entrepreneurial educational and support programs in order to enhance the establishment of new business between rural and urban areas

Agricultural Policy, Off-farm Income, and Farmland Values: The Case of South Korea

Farmland plays a dual role for farm business households; it can be both a production cost and an asset. As a production cost, farmland affects farm production decisions. As an asset, farmland comprises 80% of the total farm households’ assets. The total land available for farming is decreasing due to non-farming demand for land. The primary goal of this dissertation is to examine the impact of farm household income on farmland values. Specifically, I will assess the impact of off-farm income and government subsidies on farmland values in South Korean farm households. The majority of the studies on off-farm income, government agricultural subsidies, and farmland values have been conducted using either United States or other developed countries’ data. This dissertation contributes to the literature by investigating the impact of off-farm income and government subsidies in Korean agricultural households. Examining Korea’s situation will improve the decision making of farm policymakers and researchers who are interested in reducing agricultural subsidies and increasing the economic well-being of Korean farm households

How to juggle work & family: a mixed method study on home-based mom teleworkers

This study investigates how boundary management between childcare and work affects the practice of telework. Such approach is meaningful since the employees’ initial motivation to work away from the office is likely to influence the actual practice of telework, which in the case of Korean women were childcare. We observed home-based women teleworkers who are concurrently taking care of their child, principally focusing on how child caring context affects individual and collaborative working behavior, as well as information device usage. Multi-angled observations, including surveys, in-depth interviews, and data log analysis were conducted, to investigate the practical difficulties women encounter while working at home. Our findings show that at an individual level, child-centric time management influenced the type of tasks possible. At a collaborative perspective, this also intensified asynchronicity. Lastly, mothers were frequently in a physically dynamic state, thereby showing notable use of mobile devices and hands-free input

Effect of magnetic Gd impurities on the superconducting state of amorphous Mo-Ge thin films with different thickness and morphology

pre-printWe studied the effect of magnetic doping with Gd atoms on the superconducting properties of amorphous Mo70Ge30 films. We observed that in uniform films deposited on amorphous Ge, the pair-breaking strength per impurity strongly decreases with film thickness initially and saturates at a finite value in films with thickness below the spin-orbit scattering length. The variation is likely caused by surface-induced magnetic anisotropy and is consistent with the fermionic mechanism of superconductivity suppression. In thin films deposited on SiN the pair-breaking strength becomes zero. Possible reasons for this anomalous response are discussed. The morphological distinctions between the films of the two types were identified using atomic force microscopy with a carbon nanotube tip

A Location-Planning Decision-Support Tool for Tradeshows and Conventions

This report introduces a strategic decision-support tool for location planning in tradeshows and conventions. This decision support tool is based on a multi-year research project that examined tradeshow participants preferences, including a comparison of attributes sought by attendees and by exhibitors. The study, supported by the Cornell Center for Hospitality Research and ASAE Foundation, included a survey of over 2,500 tradeshow participants who indicated that the show’s location is one of the top criteria. In addition to its examination of tradeshow attributes, this report describes the research process, gives an outline of customer choice, and explains how the tool can be used in an effective location and planning decision process for tradeshows considering attendees’ and exhibitors’ preferences

case of automotive industry

Thesis(Doctoral) --KDI School:Ph.D in Public Policy,2010Outstandingdoctoralpublishedby Hyunjeong Kim

Superconductor Insulator Transition in Long MoGe Nanowires

Properties of one-dimensional superconducting wires depend on physical processes with different characteristic lengths. To identify the process dominant in the critical regime we have studied trans- port properties of very narrow (9-20 nm) MoGe wires fabricated by advanced electron-beam lithography in wide range of lengths, 1-25 microns. We observed that the wires undergo a superconductor -insulator transition that is controlled by cross sectional area of a wire and possibly also by the thickness-to-width ratio. Mean-field critical temperature decreases exponentially with the inverse of the wire cross section. We observed that qualitatively similar superconductor{insulator transition can be induced by external magnetic field. Some of our long superconducting MoGe nanowires can be identified as localized superconductors, namely in these wires one-electron localization length is much shorter than the length of a wire

Entrusted or Directed Subsidies in WTO Disputes

Entrusted or directed subsidies occur where a government or public body grants a subsidy by acting through private parties. Article 1.1(a) (1)(iv) of the Subsidies and Countervailing Measures Agreement allows for such subsidies to be caught by the regulation of World Trade Organization. The interpretation of entrusted or directed subsidies has been the subject of a string of Panel and Appellate Body rulings. The interpretation was restrictive at the first step, but there has been a loosening of the notion of entrustment or direction and the corresponding evidentiary standard. In this regard, this study attempts to analyze comparatively and comprehensively the legal criteria for defining entrusted or directed subsidies rendered in disputes involving Hynix, a South Korean manufacturer of semiconductors and memory chips. This study also explains a series of restructuring programs for Hynix and how they were addressed in different dispute

日本語と韓国語における新語の対照研究 : 混種語における外来要素を中心に

広島大学(Hiroshima University)博士(学術)Doctor of Philosophydoctora